IMU

Table of Content

LAB#

Add IMU sensor to sdf
Bridge to ROS2
Show in RVIZ

sdf#

Add sensor sdf under link
Add imu plugin

Add plugin tag under world tag

<plugin filename="libignition-gazebo-imu-system.so"
        name="ignition::gazebo::systems::Imu">
</plugin>

Add sensor to imu_link tag

<sensor name="imu_sensor" type="imu">
    <always_on>1</always_on>
    <update_rate>1</update_rate>
    <visualize>true</visualize>
    <topic>imu</topic>
</sensor>

Check this link for more info #

tf#

Add static tf between sensor frame to link frame

static tf

Sensor has fix frame_id, set from it’s location We need to set static tf form link frame to sensor frame_id

imu_tf = Node(
    package='tf2_ros',
    executable='static_transform_publisher',
    name="imu2imu_link",
    arguments = ["0", "0", "0", "0", "0", "0", "imu_link", "basic_mobile_bot/imu_link/imu"]
)

bridge#

bridge source code

Add imu msg bridge
Set QoS to best_effort
Add tf static transform from imu_link to sensor frame_id basic_mobile_bot/imu_link/imu

bridge

imu_bridge = Node(
    package='ros_gz_bridge',
    executable='parameter_bridge',
    arguments=['/imu@sensor_msgs/msg/Imu@gz.msgs.IMU'],
    output='screen',
    parameters=[{
        'use_sim_time': use_sim_time,
        'qos_overrides./imu.publisher.reliability': 'best_effort'
    }]
)

before qos convert

ros2 topic info /imu --verbose
Type: sensor_msgs/msg/Imu

Publisher count: 1

Node name: ros_gz_bridge
Node namespace: /
Topic type: sensor_msgs/msg/Imu
Endpoint type: PUBLISHER
GID: 01.0f.64.c6.90.63.0b.31.01.00.00.00.00.00.14.03.00.00.00.00.00.00.00.00
QoS profile:
  Reliability: RELIABLE
  History (Depth): UNKNOWN
  Durability: VOLATILE
  Lifespan: Infinite
  Deadline: Infinite
  Liveliness: AUTOMATIC
  Liveliness lease duration: Infinite

imu message after qos convert

ros2 topic info /imu --verbose
#
Type: sensor_msgs/msg/Imu

Publisher count: 1

Node name: ros_gz_bridge
Node namespace: /
Topic type: sensor_msgs/msg/Imu
Endpoint type: PUBLISHER
GID: 01.0f.64.c6.fb.16.9f.99.01.00.00.00.00.00.14.03.00.00.00.00.00.00.00.00
QoS profile:
  Reliability: BEST_EFFORT
  History (Depth): UNKNOWN
  Durability: VOLATILE
  Lifespan: Infinite
  Deadline: Infinite
  Liveliness: AUTOMATIC
  Liveliness lease duration: Infinite

usage#

terminal1

ros2 launch ign_tutorial ign.launch.py with_bridge:=true

terminal2

ros2 run rqt_robot_steering rqt_robot_steering

terminal3

rviz

IMU